| 摘要 |
<p>A powder actuated tool (20) for driving a fastener (42) into a concrete steel or other hard surface (48). The tool (20) has a main housing (28) in which a barrel assembly (27) is held. The barrel assembly (27) is permitted to move in and out a short distance and is spring loaded in the out position. A cartridge (32) is held at the inner end of the barrel (27). A piston (35) is held within the barrel (27) and has an upper end (45') near the cartridge (32) and a lower end (40) adjacent a fastener (42) to be driven. When the cartridge (32) is detonated the piston is driven against the head of the fastener (42) driving it into the concrete or other substrate (48). A firing pin (38) is held in a breech block (36) and is moved downwardly by contact with a firing hammer (37). The firing hammer (37) is also held by the breech block (36) and is spring loaded to move downwardly. Its downward movement is restrained by the contact of a tab (53) resting on a ledge (52) of the breech block (36). When the firing hammer (37) is turned the tab (53) falls into the slot (52) causing the firing hammer (37) to move downwardly and contact the firing pin (38) thereby detonating the cartridge (32) and driving the piston (35) and eventually the fastener (42). The firing hammer (37) is twisted by twisting the end handle (22) of the tool (20).</p> |
